Calcining-furnace.



PATENTED MAY 5 C T. HENNIG. GALGINING FURNAGE. AnfLIonIoN FILED 001.4, 1899.

N0 MODEL.

l. Annu A r v WiFi-estres NITED STATES Patented May 5, 19GB.

PATENT OFFICE.

CHARLES THEODORE HENNIG, OFLONDOYN, ENGLAND,VASSIGNOR TO- JAMES l ROBINSON IIATMAKER,;OF LONDON, ENGLAND.

cALclgNlNc-FURNACE.

SPECIFICATION forming part bf "Leners :Patent No. 7.0.6,915, dated May 5, 1903.

Application filed October l 1899.

To all whom it may concern:

Beit known that-I,CHARLES THEODORE HENNIG, a citizen of the United Sta-tes of America, residing in London, England, have invented a certain new and useful Improvement in Calc'ining-Furnaces, of which the following is a specilicatiom Owing to the tendency of heated gases to rise and to pass rapidly through a tube of limio ited length the heat introduced into the rotaryfurnaces at present used for calcining materials is but poorly utilized, and besides waste of heat considerable power is'required to revolve such furnaces.

My objects are to effect a higher utilization of the heat employedin calcining and to reduce the expenditure of power in connection with such processes, and to accomplish thesev ends I construct a furnace consisting of a sieprefer to make thechambers stationary and more or less flat or low in cross-section, so as to keep the heated gases down near the load to be acted upon; but my invention is not limited in its application toa series of chambers of a particular cross-section nor to stationary chambers, for a series may include rotary, rocking, or other movable chambers. 4o In practice the chambers made be made longer or shorter, thenumber in a series may be two or more, and their degrees of inclination may vary. I prefer to make the lower or final chamber of my series vertical andsta- 4 5 tionary, so that the materials treated mayfall through it to its point of discharge, the heated gases being introduced into said iinal chamber near its lower end above its point of discharge and rising upward through it intoV 5o and through the chamber or chambers above it. The chambers in any given series are serai No. 'ls.471. oto mat-.1.)

suitably connected to prevent escape of heat and to facilitate the passage of materials. A screw or other suitable conveying means may beemployed in stationary chambers to facili- .tate the passage of materials through them, and baffles may be constructed inside the chambers to deflect or retard the passage of the heat.

My invention is illustrated by the construc- 6o tions shown in the accompanying drawings, in which like parts are designated by like numbers and letters.

Figure I shows a continuous furnace, composed of two descending stationary chambers A and B and a final vertical stationary charnvber C. The two upper chambers are made low in cross-section and are fitted with screws 3 3 to assist the passage of materials through them. These screws are supported by hang- 7o ers or supports 6 -6 and are connected outside the chambers by a bevel-gear 5 and revolved by power applied at pulley 4. Materials introduced at l, after passing through the furnace, are discharged at 2. Heated gases from -any convenientsource, as from the combustion of pulverized coal,are introduced at 7 and, passing upward, carrying the evaporations withthem, find an outlet at 8. A door is provided at 9 to admit of access to the chambers, 8o if necessary. A baffle or deector is shown at V10.` Cast-iron or other suitable plates may be inserted along the bottom of the'upper chambers to lprotect the lining from the wear of lthe screwsand of the materials. It will be noticed that no conveying means whatsoever are required in my final Vertical chamber, the

materials falling through it by gravity. I lay particular stress upon the practiticalim-- portance and Value of this final chamber of -9o` myseries, for-it enables a result to-be brought aboutwhich is very desirable in the calcination of various materials-namely,.a thorough exposure of the materials to be treated to the gases when they are rst introduced and at their highest temperature, 'the gases rising through the falling materials. I prefer to make the walls of. this final chamber 'slightly expanding from top to bottom to prevent contact and adherence of the materials falling roo through it.

Fig. II shows my furnace composed of a descending stationary chamber A, a descending rotary chamber D, and a final Vertical stationary chamber C. This substitution of a rotary chamber in place of the stationary chainberB (shown in Fig. I) is desirable where higher heats are employed, as a rotary chamber is revolved by external application of power, and no internal conveying means which might be unfavorably affected by high temperatures are required. A rocking chamber may be used instead of the rotary chamber without departing from my invention.

Fig. III is a cross-section showing my preferred form of stationary chamber with screw 3 in position and hanger 6 and protectingplate 1l. I

It will be understood that the furnace should be built of suitable fire-resisting materials and that the screws or other conveying means within any of the chambers should be made of metals capable of withstanding the elects of the heat employed. For high heats I have found nickel alloys to be the mostsuitable. -Thebearingswithinthechambers should be of graphite or equivalent material.

Although my furnace is especially suited to high temperatures and I have referred to it herein as a calcining-furnace, it may be used with advantage for roasting or drying at lower temperatures than are ordinarily required for caloining, and I wish it understood that I do not limit its use to what might strictly be called calcining l. A furnace in which materials to be treated are brought in to direct contact with heated gases, the said furnace consisting of a final.`

vertical stationary empty chamber in combination with a number of chambers above it, all of the said chambers being connected and so constructed that each successive chamber in the series forms an angle with thechamber preceding it, the said final chamber being of considerable length and having an opening for the admission ot' heated gases near its lower end so that the materials falling through it may be thoroughly exposed to the action of the heated gases rising through it and having an opening for the discharge of materials at its lower end below the said admission-opening, the first or uppermost chamber in the series having an opening or openings for the escape of the gases and evaporations and the admission of materials, substantially as described.

2. In a furnace of the class described the combination of one or more interiorly horizontally flattened stationary chambers provided with internal conveying means with a inal vertical stationary empty chamber of considerable length and having an opening for the admission of heated gases near its lowerend so that the materials falling through it may be thoroughly exposed to the action of the heated gases rising through it and having an opening for the discharge of materials at its lower end below the said admission-opening, the said iiattened chamber or chambers being placed above the said nal chamber, all of the said chambers being connected and so constructed that each successive chamber vin the series forms an angle with the chamber preceding it, the first or uppermost chamber in the series having an opening or openings for the escape of the gases and evaporations and the admission of materials, substantially as described.

CHARLES THEODORE IlEilNlG. Witnesses:

H; D. JAMESON, T. L. RAND. 

